Planoqraph co



T. K. NORTH.

SUYBMARINE MINE. APPLICATION FILED JUNE 2|, 1911.

Patented Aug. 5, 1919.

B 7. flame:

THE COLUMBIA PLANUGRAPH CO WASHINGTON, D C.

UNITED STATES PATENT OFFICE.

THOMAS KEPPEL NORTH, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNOR T0 VICKERS LIMITED, OF WESTMINSTER, ENGLAND.

SUBMARINE MINE.

Application filed June 21,

To all whom it may concern:

Be it known that I, THOMAS KEPPEL NORTH, a subject of the King of Great Britain, residing at Vickers House, Broadway, Westminster, in the county of London, England, have invented certain new and useful Improvements in or Relating to Submarine Mines, of which the following is a specification.

This invention relates to submarine mines of the kind in which a flotation chamber or mine proper, an anchor, and a plummet or sounding ball are employed, the anchor being connected to the flotation chamber by a cable (hereinafter referred to as a mooring cable) which is paid out from a drum in the anchor during the separation of the anchor and flotation chamber, the plummet being connected by a line to a device for stopping 4 the paying out of the cable when the plummet reaches the sea bed during the descent of the anchor. This stopping device usually comprises a spring controlled pawl adapted to engage with teeth formed on a drum upon which the cable is wound and the said plummet is usually supported by a hook from which it is detached at the time of launching the mine and from which it is also liable to become released unintentionally.

According to the present invention I provide a plummet supporting device which is controlled by the paying out of the mooring cable in such a manner that it retains the plummet locked to the anchor until after a predetermined length of the mooring cable has been paid out, thus insuring that it cannot be unintentionally released.

When the plummet is liberated it falls away from the anchor to a depth depending on the length of the plummet line and finally operates to stop the revolution of the paying out drum in the usual manner. For the purpose of my invention a screw threaded nut mounted on a screw threaded portion of the axle of the cable paying out drum and normally held against rotary motion, cooperates with lever mechanism forming part of the plummet supporting device so that after the cable paying out drum has performed a certain number of revolutions the nut reaches a position in which it liberates the said lever mechanism and permits the plummet to escape from its support.

In order that the said invention may be clearly understood and readily carried into Specification of Letters Patent.

Patented Aug. 5, 1919.

1917. Serial No. 176,059.

effect the same will now be described more fully with reference to the accompanying drawing, in which Figures 1 and 2 are longitudinal sections of a mine anchor showing my improvements applied thereto; Fig. 1 illustrating the position of the parts before the release of the plummet and Fig. 2 after the release.

A is the plummet and B is a chain connecting it to a spring controlled lever C which is indicated diagrammatically at m and which operates to stop the paying out of the mooring cable in the usual manner. D is the anchor paying out drum which is fixed to the axle E. F is the screw threaded portion of said axle and G is the nut mounted thereon and prevented from revolving by a spring controlled plunger 0 hereinafter more fully referred to. H is a rod which is pivotally connected at one end to a lever I, its other end passing through a guide J and resting upon the nut G. The lever I is pivotally connected at K to a bracket L secured to the anchor' casing and having a part L located outside the anchor casing to which the hook is pivotally connected at L The toepiece or inner end of the hook M is formed with an inclined face i which normally lies against a similar surface I on the lever I. N is the eye on the plummet A which engages with the said hook M. When the parts are in the position shown in Fig. 1 theplummet is positively locked to the an: chor, but when the mine is launched and the cable paying out drum D rotates owing to the separation of the flotation chamber from the anchor the nut G is caused to move along the axle E until it no longer supports the rod I-I, whereupon the weight of the plummet is able to rock the hook M, about its fulcrum by displacing the rod I-I into the position shown by Fig. 2, thus liberating the device (which per se forms no part gage with the toothed wheel Q, has been over come by the weight of the plummet. This anti-vibration device comprises a spring controlled plunger 0 one end of which engages the nut G as aforesaid so as to prevent its rotation although allowing it to travel longitudinally. The other end of the plunger 0 engages with the locking lever C and in the position of the parts shown in Fig. 1 prevents the said lever from engaging with the toothed wheel Q. When the nut has moved out of the path of the plunger 0, as shown in Fig. 2, the said plunger isforced upward by its spring and releases the looking lever C. Thereafter when the plummet reaches the sea bed and its weight is taken off the locking lever O the action of the spring of the locking lever G forces the said lever G into engagement with the toothed Wheel Q and stops the further paying out of the mooring cable.

What I claim and desire to secure by Letters Patent of the United States is 1. A submarine mine comprising a flotation chamber, an anchor, a mooring cable connecting said anchor to said flotation chamber, paying out gear for said mooring cable a plummet, and plummet retaining means controlled by the paying out of the mooring cable said means being so constructed as to hold the plummet attached to the anchor casing until the mine has been launched and a predetermined length of the mooring cable has been paid out.

2. A submarine mine comprising a flotation chamber, an anchor, a mooring cable connecting said anchor to said flotation chamber, paying out gear for said mooring cable, a plummet, plummet retaining means controlled by the paying out of the mooring cable, said means being so constructed as to hold the plummet attached to the anchor casing until the mine has been launched and a predetermined length of the mooring cable has been paid out, and a device controlled by said plummet for stopping the paying out of the mooring cable when the plummet reaches the sea bed.

3. A submarine mine comprising a flotation chamber, an anchor, a mooring cable connecting said anchor to said flotation chamber, paying out gear for said mooring cable, a drum forming part of said paying out gear, an axle for said drum formed With a screw threaded'portion, an axially movable screw threaded nut mounted on the screw threaded portion of said axle, means for restraining said nut against rotary motion, a plummet, a plummet supporting device on the anchor casing, and locking means controlled by the paying out of said mooring cable and the axial movement of said nut which cause the said plummet supporting device to release the plummet when the mine has been launched and a predetermined length of the mooring cable has been paid out.

4:. A submarine mine comprising a flotation chamber, an anchor, a mooring cable connecting said anchor to said flotation chamber, paying out gear for said mooring cable, a drum forming part of said paying out gear, a toothed wheel forming part of said drum, a stopping device comprising a spring controlled pawl adapted to engage said toothed wheel when the plummet reaches the sea bed, a connection from said stopping device to said plummet, an axle for said drum formed with a screw threaded portion, an axially movable screw threaded nut mounted on the screw threaded portion of said axle, a spring controlled plunger, one end of which normally restrains said nut against rotary motion and the other end of which normally acts to hold said spring controlled pawl out of engagement with said toothed wheel, a plummet, a plummet supporting device on the anchor casing, and means controlled by the paying out of said mooring cable and the axial movement of said nut which cause the plummet to become disengaged from said supporting device and fall away from said anchor to a distance determined by said connection; the continued axial movement of said nut thereafter acting to free the said spring controlled plunger.

5. In a submarine mine comprising an anchor, a flotation chamber connected to said anchor by a mooring cable, and a plummet line which controls the distance that said plummet, when released, can fall away from said anchor, the provision of means which cause said plummet to separate from said anchor to a distance determined by the length of said plummet line when the mine has been launched and a predetermined length of the mooring cable has been paid out.

In testimony whereof I aflix my signature.

THOMAS KEPPEL NORTH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

